Conventionally, users of computing devices, such as personal computers, utilize computer cards which are inserted into the host computer to provide hardware expansion or peripheral functions. For example, computer cards may provide memory expansion, data storage, or input/output functions. Many of these computer cards are manufactured in accordance with PCMCIA (Personal Computer Memory Card International Association) standards and are therefore referred to as PCMCIA cards. PCMCIA cards utilize a standardized sixty-eight (68) pin interface for easy interchangeability between different host computers.
Computer cards are typically powered by a battery, which provides power for operations such as memory retention and peripheral functions. Because of their typically small size, conventional computer cards utilize a very small battery, the capacity of which varies inversely with the amount of current supplied by the battery. The use of the smaller battery is generally not critical in computer cards which are employed solely as data storage devices because data storage functions typically use small enough amounts of current that the battery may last for several years.
However, computer cards which provide peripheral functions, i.e., functions in addition to data storage, may require a much larger amount of current. As a result, the battery included within a computer card which provides peripheral functions, i.e., a peripheral card, may be depleted more quickly than the battery included within a computer card having only data storage functions. By way of example, a peripheral card such as a radio frequency (RF) modem, which receives and processes RF signals, typically requires a relatively large amount of current to perform the peripheral operations. This large amount of current must be supplied by the battery not only when the card is detached from the host computer, but also when the card is coupled to the host computer. As a result, the battery life of a battery utilized by such a computer card is usually relatively short.
Thus, what is needed is a computer card, such as a PCMCIA card, which, when coupled to a host computer, is powered by the host computer, thereby increasing the life of the battery utilized by the computer card.